Had a low battery light on then My car lost power steering and my gauges went crazy and the battery died, I replaced the battery and now it wont start, I have no dome lights, door locks, and the Stereo wont keep a time, keeps going back to 12:00, Also My fuel pump(which is fine) wont kick on at all, The car will start for 1-2 seconds and then shut down. Also i did think that it was the security system but i had a tool hooked up and its not give any codes. and the security light isn't on. Also i have a service wrench light on and service engine soon light is on the ABS light is on and the Brake light is on. So im wondering if its the BCM that is the problem?

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Year, engine? The one giveaway to poor battery connections is the radio clock resetting. Either examine both battery cables carefully, including the other ends, for signs of corrosion and ensure clean corrosion-free connections or struggle with a power distribution problem.

Ignore error lights for now as poor electrical connections makes the entire EFI system go nuts. Chase the power problem first.

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I changed The Battery terminals due to corrosion but there was no change, still same symptoms, its a 2003 vue with a 3.0L AWD automatic

How did you change the battery terminals? By replacing complete cable from battery to distant end or use the type that attaches to end of existing cable?

You could revisit the positive terminal to note the large wire leading to starter and smaller red cable which connects to under-hood fuse and relay box (UHFRB).

The smaller cable carries voltage for fuel, ignition, lighting, etc and should be corrosion free on each end.

You could also run your hand along the smaller cable examining for bumps or knots under the insulation - especially near the battery terminal. These are signs of internal corrosion and will cause problems similar to yours.

I checked over all 4 cables coming from the battery and only a problem with corrosion on the positive no bumps or cuts or anything really that would be a problem, ordered a used bcm off the net same year model and such very close to my original miles and if it works I might just get the ignition switch and keys also from the donor VUE, looked around for someplace to program a new one had no luck, even at the GM dealer, the BCM should be here Friday and well see. thanks for the help so far.

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I'd try to obtain key fobs mating with BCM - could save a trip to dealer.

Probably should also mention the "new" BCM probably won't be compatible with Passlock voltage provided by the old ignition cylinder.

The learn process is simple but takes about 30 minutes:

30-Minute Learn Procedure

1. Turn ON the ignition, with the engine OFF.
2. Attempt to start the engine, then release the key to ON, vehicle will not start.
3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
4. Turn OFF the ignition, and wait 5 seconds.
5. Repeat steps 1-4 two more times for a total of 3 cycles/30 minutes. The vehicle is now ready to relearn the Passlockô Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.

Important: The vehicle learns the Passlockô Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

6. Start the engine. The vehicle has now learned the Passlockô Sensor Data Code and/or password.
7. With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

New BCM installed today, ran the relearn procedure and she fired right up, Ive heard I can reprogram my key fobs to work not sure if that's true or not but the only problems I got now 1. which isn't really a problem is my miles are off as expected i to be. and 2 my battery light wont go off, not sure why?

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New BCM installed today, ran the relearn procedure and she fired right up, Ive heard I can reprogram my key fobs to work not sure if that's true or not but the only problems I got now 1. which isn't really a problem is my miles are off as expected i to be. and 2 my battery light wont go off, not sure why?

Good for you!!! Can I ask where you obtained BCM?

Check battery voltage with engine off - looking for around 12.5 volts.

Check again with engine at idle with lights, radio and HVAC fans off - look for at least 13 volts and the level should increase when engine is revved.

The attached thumbnail will give you an idea of charging scheme. Technically the ECM is in charge of controlling generator charge rate. You moved many wires early on so perhaps something has worked loose.

A not so pleasant thought is the BCM is the data-stream gate keeper but I don't know if it can affect just one function such as battery not charging.

But on other hand you apparently had battery charging problems when the ordeal started.

Well one of the functions if the BCM is battery protection but this on was tested and is in 100 percent shape so I know that's not the problem im going to check the alternator today and see if that's the problem if not then I get to check all the wiring which isn't a fun time, but I got the BCM from a place called Seymour Auto in CT.

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